31538913 has 16 divisors (see below), whose sum is σ = 48307200. Its totient is φ = 17929296.

The previous prime is 31538887. The next prime is 31538951. The reversal of 31538913 is 31983513.

It is not a de Polignac number, because 31538913 - 2¹⁰ = 31537889 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (31538113) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 406 + ... + 7952.

It is an arithmetic number, because the mean of its divisors is an integer number (3019200).

Almost surely, 2^31538913 is an apocalyptic number.

It is an amenable number.

31538913 is a deficient number, since it is larger than the sum of its proper divisors (16768287).

31538913 is a wasteful number, since it uses less digits than its factorization.

31538913 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7756.

The product of its digits is 9720, while the sum is 33.

The square root of 31538913 is about 5615.9516557748. The cubic root of 31538913 is about 315.9479731951.

The spelling of 31538913 in words is "thirty-one million, five hundred thirty-eight thousand, nine hundred thirteen".